We just got our 6.5 month old GSD spayed, and she is said to have perfect hips, no signs of HD. But he said she has a overly curved knee he isn't liking the look of, it's said that it could just be a growth development problem, but I don't know much about it, we're about to pick her up and I'm sure he'll go into more detail, but has anyone had this with their dog before?

ask your vet whether they were talking about too much turn of stifle, over angulation.
The length ratio of thigh to stifle should be about 50/50 .
Too little , too straight , may have concerns for cruciate ligament damage .
Too much and concerns for knee instability .
Does the dog walk on her hocks?